Corrugated paperboard production line paste technology and problem solving

The rapid development of domestic corrugated cartons has led most cartons to change their original single-sided machines to high-end lines. However, many companies have not changed the production of personnel and paste. They still use the method of pasting paste in the 1980s. It is understood that there are still raw materials using foaming alkali (because the foaming alkali is a toxic raw material), and the carton remains in some places. The better, not considering the carton's ability to resist pressure. As in recent years, the competition in the Yangtze River Delta region has become increasingly fierce. Most companies use high-end production lines to produce low-end products, blindly looking for low-cost and low-cost products. The quality of the base paper to reduce production costs, regardless of the entire company's profit and loss. For example, the production cost of the production department, due to the imperfect production technology, some technical personnel refused to accept new ideas, operation methods, and management methods. As a result, a large number of products were scrapped, production costs were increased, and management profits could not be obtained. How can the carton factory reduce "loss, production costs" and increase profits?

How does the carton plant wear out? We know that the main problems affecting quality are people, machines, materials, methods, and rings. When we have people, machines, methods, and rings that are unchanged, the change of raw materials will directly affect quality.

Paste is an indispensable raw material in the manufacture of corrugated board. According to statistics, its cost is 1% of the original material cost. It looks insignificant, but the change in paste quality will greatly reduce your quality. After the product is scrapped, it is so small that the product has light defects. Next, let's talk about some technical data about the paste, the configuration of the paste making equipment and the paste formulation

Several technical data on paste

A. Solids content of paste
B. Pasting temperature of paste
C, sticky viscosity

Paste solid content: The content standard is ?R25DSC. (When producing micro-shaped corrugated, the solid content must be increased)

The formula is: starch water doubled rate = (starch weight - starch moisture content) / water weight × 100%

Test method is: take an aluminum paper weighing weight W1

Take a certain amount of paste to weigh W2

After the paste is dried, the weight W3

Paste solid content = (W3-W1)/(W2-W1) × 100%

The general carton factory makes the quality control department responsible for measuring the value of solid content every week and then hand it over to the production technology department so that the production department can be sure when it comes to production.

Pasting temperature of paste: Standard is 58±2°C

Definition: The temperature required for the paste to change from raw rubber to hot glue: It influences the temperature of gelatinization and the amount of water and alkali used when making the paste.

Paste viscosity: The extent to which the glue liquid flows.

Pasting equipment

Paste barrel

a) Volume: Generally 1500 to 2500 liters is more appropriate, depending on the size and production volume of the corrugated board production line

b) Speed: generally 250 ~ 300SPM better, according to the size of the mixing blade surface, speed is too fast, easy to cause paste splash, viscosity is not easy to judge, the speed is too slow, the blade stir friction generated by the intensity is not enough, the viscosity rise Slow, easy to produce agglomerates.

c) Blade shape: mostly spiral, but ideally sheared.

d) Blade position: The mixing blade must be in the minimum of paste making.

e) The volume is large, and the paste-making personnel have sufficient time to control the quality of the paste, but the control of the bitter quality is not good because it is less easy to correct the mass.

The volume is small: the number of people making the paste is high, but if the quality control is not good, because the amount is small, it is easy to correct.

f) Other devices such as steam heating devices, temperature display meters, etc.

2. Storage barrel

A. Volume: Generally 1500 to 2500 liters is preferred.

B. Speed: Generally, 12RPM is the majority. If the rotation speed is faster, intermittent control is required. For example, stop for 2 minutes and 8 minutes.

C、Others: It has the function of heat preservation circulating water (used in winter to make the paste stable)

Paste formulation:

Standard barrel method modified two barrel method

Water (31～35)°C 600～900KG 600～900KG
Starch 175KG 175KG
Caustic Soda 4～8KG 3～5KG
Borax 1～3KG 2～5KG
Stabilizer 1.7～2.5KG ----
Crosslinking agent 5～10KG 5～10KG
Enhancer 6~10KG 6~10KG

(to be continued)